When using the Crane valve spring micrometer like this one


To install the beehive PAC1218 springs or comp 918 springs, the retainer fits down inside the lip of the mocrometer top.

Is the depth of this recessed area 0.150" ??

So when measuring for the install height of 1.75" you really want to see 1.90" on the micrometer to compensate for the recessed lip the retainer fits down into right??

 

I don't know the depth of the reccessed area on that mic. But, yes you should add the difference.

Are you sure you want to install those springs at 1.75?

 

Specs call for 1.75-1.8" recommended install height. Bind is at 1.14" so that gives you room for up to .610 lift. Any more install height will give you less initial seat pressure. Lift on the cam is .560 w/ 1.6 rr's so I should have plenty of room with the recommended .1 cushion and with the nitride treated 1518s the bind height is even less than the 1218s.
Load @ 1.80 is 130 lbs, so the .05 shorter install height will result in an open load of 145 lbs.

 

I have the same spring mic and mine is .150" to the first shoulder. Your
math is correct. If you are shooting for 1.75" then the reading with the
beehive retainer on the first shoulder should be 1.90". Remember to give
each valve stem a tap once the mic is tightened as the locks may need
to seat.